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<div><span class="kw">theorem </span><a NAME="T21"><span class="comment"><font color="firebrick">:: RELSET_1:21</font></span><br/></a><div class="add"> for <font color="Olive" title="b1">X</font>, <font color="Olive" title="b2">Y</font>, <font color="Olive" title="b3">Y1</font> being    <a href="hidden.html#M2" title="HIDDEN:mode.2">set</a> <br/>  for <font color="Olive" title="b4">R</font> being   <a href="relset_1.html#NM1" title="RELSET_1:NM.1">Relation</a> of <font color="Olive" title="b1">X</font>,<font color="Olive" title="b2">Y</font>  st <font color="Olive" title="b2">Y</font> <a href="tarski.html#R1" title="TARSKI:pred.1">c=</a> <font color="Olive" title="b3">Y1</font> holds <br/><font color="Olive" title="b3">Y1</font> <a href="relset_1.html#K6" title="RELSET_1:func.6">|`</a> <font color="Olive" title="b4">R</font> <a href="relset_1.html#R2" title="RELSET_1:pred.2">=</a> <font color="Olive" title="b4">R</font></div></div>
